Ventilating fan



July 30, 1957 c. BREIDERT VENTILATING FAN Filed Aug. 1, 1955 FIG. 3

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INVENTOR GEORGE 0. BREIDERT ATTORNEYS United States Patent VENTILATING FAN George C. Breidert, LaCanada, Calif.

Application August 1, 1955, Serial No. 525,602

Claims. (Cl. 310-60) This invention has to do with ventilating fans and relates more particularly to motor-driven fans incorporating means for protecting and cooling the fan motor.

Ventilating fans of this type are commonly located in wall openings and usually have the driving motor positioned coaxially behind the fan and directly connected to the fan shaft, so that during operation the fan draws air over the motor. Inasmuch as such air is usually laden with dust and corrosive chemicals, the dust and corrosive chemicals become deposited on the motor. It has been proposed to place the fan motor in a protective housing and to ventilate the housing for purposes of cooling the motor. However, such attempts have not been fully satisfactory because the means provided for circulating air through the housing have not been satisfactory. For instance, it has been proposed to provide the motor housing with an air inlet duct drawing air from the front of the fan, and to provide the motor housing with a siphoning air outlet opening directly behind the center or longitudinal axis of the fan. The difliculty with such an arrangement is that there is a minimum movement of air by the central or axial portion of the fan and the siphoning effect produced by such an arrangement is too minor to be effective in satisfactorily cooling the fan motor.

It is an object of my invention to overcome that disadvantage and to provide in a fan a motor cooling arrangement which achieves maximum ventilation of the motor protective housing and hence effects proper cooling of the motor while at the same time protecting the motor from deposits of dust and corrosive chemicals.

More particularly, it is an object of my invention to provide in a fan a motor housing having an air intake whose inlet end opens radially outwardly from and forwardly of the fan periphery and having one or more air outlet ducts whose discharge ends open forwardly of and radially spaced from the periphery of the fan and are positioned to take advantage of the greater pitch and tip speed of the fan blades and thus to create a maximum air siphoning elfect.

Still further advantages will appear hereinafter.

While I shall point out in the appended claims the features of my invention which I believe to be new, I shall now, for purposes of explaining my invention, describe in detail the specific presently preferred embodiment thereof for which purpose I shall refer to the accompanying drawing wherein,

Fig. 1 is a sectional view taken on line 11 of Fig. 2;

Fig. 2 is a rear plan view; and

Fig. 3 is a rear plan view of a modified form.

Referring now to the drawing, the numeral 5 denotes a building wall or the like having a ventilation opening 6 therein. A ring 15 is mounted in the opening, the flange portion 15a of the ring being secured to the wall as by bolts 16.

A motor supporting and protecting housing 20, which preferably is in the form of a casting, is supported from the ring flange 15a by a plurality of tubular arms or conduit portions 23, 24, said arms preferably being cast 2,801,353 Patented July 30,

integral with said ring and said housing. Preferably, there are two tubular portions 24, each of which defines an air outletduct communicating with the interior of the housing at circumferentially spaced points, although I may provide only a single tubular arm 23, of double the cross-sectional area of each of the arms 24, which arm defines an air inlet duct.

The inlet end or'extremity 23a of duct 23 terminates forwardly of the plane of the front of the fan 25 and at that point is disposed downwardly so that the air drawn into the duct is not the air being exhausted by the fan.

The outlet end or extremity 24a of each of the ducts 24 terminates forwardly of the plane of the front of the fan at a point radially spaced from the fan periphery, and is preferablyjdiagonallyjcut to open in a somewhat downward and forward direction. The discharge ends of the ducts 24 being thus disposed, they are exposed to the great velocity of air being moved by the tip end portions of the fan blades and thus create the highly efliective siphoning effect.

A cup-shaped inner end portion 30 is provided for the housing, having an inner end flange 31 fitted into the contiguous end of the housing and'secured therein as by set screws 32, which set screws retain the forward end of the motor within the portion 30 with the major portion of the periphery of the motor spaced from the inner sur face of housing 20 to provide an air chamber 37 between the motor and the housing. The motor shaft 40 extends forwardly through an opening in the portion 30, which opening is lined with a bearing 41, the hub 42 of the fan being secured on the forward end of the motor shaft.

By such an arrangement the air ducts 23, 24 provide an .effective spider support for the motor housing, avoiding the necessity of providing additional supports which might produce vibrations by virtue of the air stream being drawn therearound. Being round in cross-section, the ducts aiford a minimum of interference with the air flow.

It will be understood of course that I may use only a single air outlet duct and a single air inlet duct, or I may use a plurality of outlet ducts and a single inlet duct, as described, or I may employ a plurality of both outlet and inlet ducts. For instance, in Fig. 3, wherein the parts are as before described and are given like reference numerals, I describe such a device as last above mentioned. Here, I provide two air inlet ducts 50 and two air outlet ducts 51.

I claim:

1. In ventilating apparatus for mounting in an opening in a wall, a motor housing casing having an air inlet and an air outlet, said casing being disposed at one side of said wall, an air inlet conduit communicating with said inlet, an air outlet conduit communicating with said outlet, a motor mounted in said casing, a fan disposed in said wall opening, with its inner surface towards said casing, and means operatively connecting said fan to said motor for rotation about the axis of rotation of said motor, said outlet conduit extending through said wall at a point radially spaced from the periphery of said fan and having its discharge extremity portion positioned forwardly of the outer surface of said fan and disposed radially towards the axis of rotation thereof.

2. The apparatus described in claim 1 wherein said inlet conduit has its inlet extremity portion positioned forwardly of and disposed radially away from the axis of rotation of said fan.

3. Ventilating apparatus comprising, in combination, a ring-like member arranged to be mounted in a wall opening, a motor housing casing having an air inlet and an air outlet, said casing being disposed behind the rear surface of and coaxial with said ring, an air inlet conduit communicating with said inlet, an air outlet conduit communicating with said outlet, a motor mounted in said casing, a fan disposed in and coaxial with said ring, with its rear surface towards said casing, and means operatively connecting said fan to said motor for rotation about the axis of rotation of said motor; said outlet conduit extending through said ring at a point radially spaced from the periphery of said fan and having its discharge extremity portion disposed radially towards the axis of rotation of said fan and spaced forwardly of the front surface thereof.

4. Ventilating apparatus comprising, in combination, a ring-like member arranged to be mounted in a wall opening, a motor housing casing having an air inlet in its bottom and an air outlet in its top, an air inlet conduit communicating with said inlet, an air outlet conduit communicating with said outlet, each of said conduits extending through said ring at a point radially spaced from the periphery of said fan to a point spaced forwardly of the front surface thereof, a motor mounted in said casing, a fan disposed in and coaxial with said References Cited in the file of this patent UNITED STATES PATENTS 1,096,694 De Vilbiss May 12, 1914 1,244,334 Ilg Oct. 23, 1917 1,487,766 Sutcliffe Mar. 25, 1924 1,779,657 Breidert Oct. 28, 1930 1,816,920 Sutcliffe Aug. 4, 1931 

